Learn if rubber might be your best solution for components in critical applications.
Minneapolis, Minn.—Robinson Rubber Products, a designer, developer and manufacturer of custom-molded rubber products, extruded rubber products and precision rollers, has several new capabilities to bond molded rubber components to your parts to deliver superior performance. Bonding rubber to your part can also eliminate secondary operations and extra components, plus reduce weight and costs.
A prominent manufacturer of paint spray guns was having trouble obtaining the necessary fluid resistance for the gun’s poppet valve, which controls the critical air flow during the spray gun operation. O-rings and other non-bonded seals would slip, move and break down when exposed to the chemicals in the paint, resulting in poor performance. The customer had tried a fluoroelastomer bonded to a stainless steel valve shaft, but they experienced bond failures during testing. Teflon o-rings captured in a steel gland were also tried. While the Teflon provided good chemical resistance, these o-rings proved very problematic in practical application. The rings were installed on the valve during sub-assembly, but due to the fragility of Teflon, an average of 20% of the rings were damaged in the process. This yielded a 20- 30% overall scrap rate, wasted a lot of labor, and yielded an assembly with lingering quality concerns.
Robinson Rubber came up with a solution after a complete redefining of the fluid spectrum to which the poppet valve would be exposed. “Our solution involved a fairly exotic and expensive elastomer, so we employed a cold-pot transfer molding technology. With a material costing more than $200 per pound, our transfer molding tooling provides an assured poppet assembly, while greatly reducing the waste that one would see in all other molding processes,” says Jay Beck, President of Robinson Rubber. “This elastomer holds up to a very broad spectrum of chemicals, but is difficult to successfully bond to the stainless steel poppet stem. After adjusting several mold operations, we achieved a solid bond. Our resulting product has been tested in the most aggressive solvents the guns would see, and the material and bonding perform flawlessly. We’ve been in production now over a year and we have not had one failure,” states Beck.
Not only has the new poppet valve performed well in all the painting operations, but because the elastomer on the poppet valve is so chemical-resistant, the spray guns can be used for a whole new set of applications using ketones, aliphatics, aromatics and other aggressive solvents without leaking. “This ‘better mousetrap’ has allowed our customer to sell these spray guns to boat and bathtub manufacturers who spray fiberglass, and to wind generator blade manufacturers and other OEMs who spray polyesters and polycarbonates. Our customer reports an 80% growth in new market sales,” according to Beck.
Using up to 20 engineering grade polymers and more than 2,000 unique formulations, Robinson Rubber works with you to deliver the best rubber solution possible. Let us develop a proprietary custom formula for you using our in-house compound formulation and mixing capabilities.
Substrate materials include acetal, aluminum, brass, bronze, carbon steel, copper, ductile iron, fabric reinforcement, glass-filled composites, mineral-filled composites, nylon, PEEK, PES, phenolics, PTFE, PVDF and stainless steel. Molding an appropriate rubber gasket, support, seal, o-ring, mount, bushing, cover, wheel or other part directly to your part delivers an integral part that is less likely to leak, crack or otherwise fail in the field. Bondable substrates include single or multiple component substrates that are die cast, injection molded, stamped, waterjet cut, CNC machined or wire formed. We can also bond rubber-to-metal-to-plastic-to-fabric combinations. “Providing sophisticated bonded assemblies of high quality is our specialty, with over 70% of our rubber being bonded to substrates,” says Jay Beck, President of Robinson Rubber. “This process delivers high performing components to our customers with virtually zero returns,” says Beck.
Substrate parts include but are not limited to chain pads, conveyor pads, diaphragm assemblies, electrical insulators, ground spool valves, impellers, inflatable butterfly valve seats, motor mounts, non-invasive medical devices, power drive assemblies, sanding disks, special wheels, valve assemblies, vibration isolators and vibration mounts.
If you are an engineer struggling with trying to come up with components that will perform multiple functions in challenging conditions, check out rubber’s capability to bond to a variety of substrates, eliminate parts and lower assembly costs. A Polymer and Material Selection Guide is also available.
To learn more, email email@example.com, visit www.robinsonrubber.com, or call toll free 1-877-619-2825 or 763-535-6737 for more information.